Soldering flux



' not attack or clean the surface.

Patented Dec. 2,1930

UNITED STATES PATENT OFFICE nanny c. motion, or person, mcmean, assr enoa ro' GENERAL morons-3g.

smaon coaronarron, or nnrzaorr, mcnrean, A coarona'rron or nnawaan soLnEnme run:

In Drawing.

to be soldered a flux containing cleaning and fluxing substances such as borax, zinc chlo- I ride and ammonium chloride with or without the addition of hydrochloric acid. Oily materials are often present on the surfaces to which the solder is to be applied and, in such cases, fluxes in paste or liquid form in which water alone is employed as a solvent are not entirely satisfactory for the reason that they do not. wet the oily surfaceand therefore do Inaccordance with the present invention it is roposed to emplo as an ingredient of the ux a' material which is a powerful solvent for oils and is also a common solvent for both oil and water or, in other words, is. miscible with or soluble in both oil and water,

- and is therefore capable of being used in-aque-' ous solution and in treatment of surfaces in the presence of both oil and water.

It is desirable also that the material sele :ted shall not be too readily volatile, shall not give off noxious fumesor be otherwise objectionable to workmen and that it shall not have an undesirable corrosive action upon the steel or other surfaces to which it is applied. It is preferable, although notyalways necessary, that the material shall have a boilin%point not lower than that of water.

rom the standpoint of the properties referred to and also of commercial availability I have found certain of the glycols and their ethers and esters especially suitable for use as the. oil solvent. Particular mention may be made of (1) the polyglycols, such as di-,

tri-, and tetra-ethylene glycol, i'and their ethers, especially the ethyl and butyl carbitols (ethyl and butyl ethers ofdi-ethylene glycol), (2) the methyl, ethyl and propyl ethers of either ethylene glycol or propylene glycol, also some ot er glycol ethers, as 1,4-dioxan,. (3) the acetates ofglycol and di-ethylene Application and August 19, 1929. Serial 80. $87,050.

glycol and of some of thegl col ethers. Of the acetates, the preferre examples are ethylene glycol mono-acetate, (ii-ethylene glycol mono-acetate and the acetates of the methyl and ethyl ethers of ethylene glycol.

' A1 of the above ma be grouped as water soluble oil solvents of t e glycol type and will be hereinafter so designated. By the use of. the terms oil soluble and water soluble it is not intended to limit the invention to those substances which are miscible in all proportions with oil and water. The

substance is deemed water soluble for the purposes of this invention if it is sufliciently soluble in water to 'form a solution in the concentration in which it is desired to use the material. Similarl it is oil soluble if it is capable of a tacking oil I .suificiently to cause the mixture to wet the .oil surface to which it is to be applied.

ome other esters which are both water soluble and oil soluble are also suitable for use in soldering fluxes in view of their powerful solvent action and other desirable properties and their present availability on the market. Amongthesemaybementionedethyl lactate and ethyl o cohol, CH COCH CO (0H,) is another xybut rate. Diacetone almaterial possessing to a high degree the properties rendering it desirable for this use.

A 'solderingflux which will be of a pasty consistency may be made by mixing about ten parts (by weight) of zinc chloride with about Q five parts of one of the oil above. 1

If a liquid flux is desired, the above composition may be diluted with ethyl alcohol or with water or both. For example, with about 10 parts of zinc chloride l may mix about four partsiethyl alcohol and 1-2 parts of the oil solvent, and to the composition maybe added for further dilution about five-parts of .water. A small proportion of 'sal-ammoniac may be addedto the composition if desired, particularly for use in soldering at low temperatures. I

Where the surface to be soldered-is rusty or badly oxidized it may be desirable to addto solventsmentioned the composition a small amount of a, cleaning acid, for example, hydrochloric acid.

I claim:

A soldering flux com rising zinc chloride, 5 water and a water-solu le oil solvent of the grou consisting of di-, triand tetraethy ene glycol,

ethyl and butyl carbito}, the

mono-acetates of ethylene and di-ethylene' glycol and of the methyl and ethyl ethers of 10 ethylene glycol,'ethyl lactate, ethyl oxybu tyrate and (ii-acetone alcohol.

In testimony yvherepfl afiix my si ature. HARRY C. MOU EY. 

